Granted Patent
Utility
US 4,443,206 · App. 06/346,169
Well tool
Inventor:
Chuan C. Teng
Patented Case
View Patent ↗
Granted: Apr 17, 1984
Filed: Feb 5, 1982
Inventor
Chuan C. Teng
Assignee (at issue)
Dailey, Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.